Fluid operated clutch



Aug. 31, 1943. H. NUTT ErAl.

FLUID OPERATED CLUTCH Filed Sept. 30, 1938 5 Sheets-Sheet l Aug. Y31, 1943. H.NUTT ET'AL 2,328,091

y FLUID OPERATED CLUTCHv Filed Sept. 50, 1958 5 Sheets-Sheet 2 Aug; 3l, 1943. H, NUT-r ET AL 2,328,091

FLUID OPERATED CLUTCH Filed sept. 5o, 1958 5 sheets-sheet 5 Aug. 31, 1943. H, NUTT ET AL 2,323,091

l FLUID OPERATED CLUTCH FiledSept. 3C, 1938 5 Sheets-Shea?l 4 5 Sheets-Sheet 5 Q @www Patented Aug. 31, 1943 UNITEDv STATES PATENT 2,328,091 l FLUID OPEBQATEB CLUTCH :Harold Nutt, Chicago,

Bellwood,

OFFICE f ma menno asma-1,

lll., assignors to Borg-Warner Cor` poration, Chicago, a corporation of Illinois Application September 30, 19,38, Serial No. 232.664

4s claim.. (o1. isz- 3.5)

Thisinvention, relating as indicated, to iluid operated clutches, has as its primary oblect to provide a clutch system wherein the iluid pressure is controlled by an automatic control valve,

rotating with the driving side of the clutch,land adapted to govern the engaging pressure of the clutch (within certain limits, as will be more fully explained later) in direct proportion to the speed of rotation of the clutch. It has. been pre` viously proposed to control the iluid pressure in a clutch of this general type, by centrifugal force developed ingovernor weights and transmitted ,through mechanical linkage directly to some me- `cnamcai `part of the clutch. also, 1t has been.'

.proposed to control the application of iiuid pressure to the clutch,vby a centriiugally operated valve adapted to control the flow oi' fluid to the pressure in clutch without being affected-by the the pressure chamber of the clutch.

IThe* presentinvention greatly improves upon the perfomance' and simpliiles the construction of such clutches, by providing an arrangement various parts, passages. and than prior arrangements of the kind.

Another, object of the invention is toV provide' a control valve which will not readily stick. and the action oi' which is relatively smooth.

In prior arrangements. it has been proposed to provide two iluid pumps, one driven from the engine and the other driven from the transmission, andv each having an independent fluid circuit for performing its respective functions, the engine driven pump being employed for auto- 4 matic operation of the clutch, and the transmis.-

sion driven pump 'being employed for locking out" the clutch against automatic operation during normal driving conditions and for push starting. Although in some of its aspects, the present invention contemplates improvements in this type of arrangement, one of the obiects of the present f invention is to provide a clutch system of the general type specled, whereinboth'pumps are adapted to deliver fluid -to the .clutch motor through a common uid .passagain order that wherein a control valve, arranged to rotate with one side ofthe clutch, directly impresses the centrifugal force which it develops as a result of such rotation. upon the fluid in the pressure chamber of the` clutch. To this end, the valve l is arranged so that -the ivluid in the pressurel chamber reacts against an end or ,the valve element, tending to open the valve inopposition to centrifugal force tending to close it.

Another object of the invention is to secure the same initial clutch engagement under quick acceleration of thevehicle motor, as is effected under slow acceleration. It has been found that owing to the occurrence of an interval of delay Yonly one pump housing and one set of'pump inlet antd outlet ports may be made to serve both pump roors. 1 M

This is made possibleby providing an arrangement wherein the iiuid lwhich is made available for operating the lockout mechanism. is delivered also to the clutch operated iluid motor, the same as the fluid which is delivered for 'centrifugal operation of the clutch.

in the starting of clutch engagement alter the 1 closing of the control valve at the predetermined speed, the initial engagementl occurs at a definitely higher speed under quick acceleration than under slow acceleration, and as a result, some shock occurs under the faster accelerating condition. The invention aims to eliminate this shock so that engagement is as smooth as that occurring under slow acceleration.

'To this end, the invention has as its object to provide, in a clutch system of the type mentioned, a `relatively simple control valve wherein the movable valve element ls `mounted in such a way that it is urged toward closed position by f both its own centrifugal force and its'own torsional inertia.

Another important object of the invention is' to provide a clutch system of the kind speciiied,

which is more simple in the arrangement of its Another object o1' the invention-is to provide a clutch system of the type specied, embodying a manual control valve which is not only much less complicated in constructionand arrangement than valves for the same purpose in prior contemplated structures, lbut is also capable oi' exercising more complete and more exible control over the clutch. In this respect. the invention contemplates a valve which is urged toward open position by the fluid pressure in the clutch operating motor, and toward closed position by a manual control element, connected to the valve moving elements,

position. doesnot remain in hindering relation to the valve during the centrifugal stageof opera.-

in the housing I I, and piloted at its forward end `in the rear end ofthe engine crank shaft (not tion. To this end, the invention contemplates invention will become apparent after reading y the following specincation and claims, and after considerationlof the drawings forming a part of the specification, wherein: v

Fig. 1 is an axial sectional view of a clutch system embodying the invention;

Fig. 2'is a transverse sectional view thereof, taken as indicated by the line 2-o-2 of Fig. 1;

Fig. 3 is a transverse sectional view thereof, taken as indicated by the line 3-3 of Fig. 1;

Fig. 4 is a transverse sectional View showing :a modified form of the control valve;

Fig. 5 is a detail sectional view, taken as indi.- cated by the line 5-5 of Fig. 3, the valve element being shown partly in section and partly in elevation';

Fig. 6 is a View, partly'in axial .section and partly schematic, of a modified form of the invention; i i

Fig. '1 is a. transverse sectional view taken as indicated, by the line 1-1 of Fig. 6;

Fig. 8l is a sectional view taken as indicatedy by the line 8-8 ofFig. 7;

Fig. 9 is a front elevation of arportion of the control valve housing;

Fig. 10 is a'transverse sectional view of the control valve arrangement of a modified form of the invention; and

I Fig.1l.v is a transverse sectional view of a porshown).

The pressure plate I9 is urged toward engaging position by the position 25 of the fluid motor 'B, transmitting thrust `through a hub 26 to a reaction plate 21 against which one end'of the hub 26 abuts, the reaction plate in turn transmitting Y the thrust to the pressure plate I9 through the medium of struts 28 mounted in the pressure plate I9 and extending through openings 2s in the cover n.

tion of 1the control valve arrangementof another modification of the invention. I

The fluid operated clutch systemshown in Fig. 1 as an example of one form in which the invention may be embodied, comprises generally a clutch A, a fluid motor B, for operating the clutch, a control valve and lock-out unit C for controlling Athe operation of the fluid motor automatically, manual control means D, and fluid pumping means E for supplying fluid under pressure to the motor B.

All of the mechanism briefly referred to above may be enclosed in a clutch housing II provided in its lower region with a sump I2 adapted to hold a body of fluid, such as lubricating oil, for operating the clutch. The fluid motor B, the control units C and D, and the engine driven pump E, may all be enclosed in a separate compartment I3, separated from the compartment I4 in which the clutch A is contained, by a. partition wall I5 secured as at I6 to the housing II.

The clutch A may include the conventional cover plate I1, secured as at I8, to the engine flywheel, indicated in dotted lines at F, a pressure plate I9 disposed inside the cover I1 and drivingly coupled therewith by meansv of lugs 20 formed on the pressure plate I9 and extending through openings 2I in the cover I1, and a conventional driven friction disc 22 adapted to be frictionally engaged between friction faces formed on the flywheel F and pressure plate I9 respectively. The driven disc 22 is splined upon the transmission shaft 23 which may be con- Disengagement of the clutch is effected by retractor springs 30, each engaged at .one end against the` cover I1, and at its other end against a washer 3| tied to the pressure plate I9 by a llug 20 and securing element 32.

The motor B includes the piston 25 and a cylinder 33 in which the piston 25 is axially slidable. The cylinder 33 is formed as an axially extending flange on the cylinder head 34 which forms the housing of the control unit C. The piston 25, the cylinder 33, a sleeve 40, and the vcylinder head 34 form the pressure chamber 35 on the piston 25 caused by centrifugal effect inthe fluid in the balancing chamber 31 substantially neutralizes that of the fluid in the chamber 35 so as to enable the clutch to be released at high speed Without the use of excessively heavy retractor springs 30. Fluid is delivered to the chamber 31 through aport 38 in the hub 26, communicating with an annular` duct 39 which receives the leakage from the chamber 35 between the piston 25 and the sleeve 40 on which it kis mounted and preventsv the escaping oil being forced out, between the sleeves 26 and 40 to a region from whence it could not return to the sump. Excess uid may leave the chamber 31 through the annular opening 4I formed between the flange 36 and the collar 26.

The sleeve 40 is centered by means of a pilot collar 43, and loosely keyed to the clutch cover plate I1 for rotation therewith, but has suillcient free play to take care of a slight amount of misalignment.

The automatic control `unit C is mounted for rotation with the flywheel F and clutch cover I1, being secured upon the sleeve 401|. It is located against a shoulder formed in .the sleeve 40. The fluid motor B, being unitary with the control unit C, also rotates with the flywheel.

Fluid under pressure for automatic clutch operation is supplied by the engine driven pump 55, which may be of the rotary vane type of construction as shown in detail in application Serial'No. 209,450 illed by Harold Nutt and Harold V. Reed, on May 23, 1938;comprising a casing defined between the housing of the manual control unit D, an annula'r plate50l, and a ring 502; and a rotor which is mounted upon the sleeve 40 so as' to be driven from the flywheel F. One of the varies of the pump is shown in cross-section at The ouuei of the pump, which nes entirely beventionally journalledin a bearing 24 mounted 75 the housing 50, is indicated at dotted lines at 46 in 1. The inlet of the pump, which may be located substantially yopposite the outlet, is-

not seen in Figure l; The annular channel y582 in the' housing, appearing in Figure 1. forms a continuation of the outlet port 4.8 and supplies' fluid under pressure ,behind the vanes lll for urging them outwardly.A

From the discharge port,V the iluidmay passl through a short axially extending port Il- (Fig. 2l into a radial passage 48, thence into 'an' .annular duct 48. all formed in the housing I8 ofthe man,-

sure chamber I of the motor-13.'4

Referring now to Fig. 3, the automaticcontrol" unit C includes' the housing Il', thecontrol valve, indicated generally at I8. and the lock-out device, which, in this form of the invention, com

' prises a valve. indicated generally at Il; i i l The control valve comprises a valve .element 58 positioned 1n `valve chamber |58 formed in chamber 88 of the fluid motor B is communicated the valve chamber 88 which is open at.. one side will be described more fully hereinafter. Communication between the pressure chamber and automaticl control valve is established through a port 68 leading ,from the pressure chamber 85 into the'chamber 88 of the lock-out valve 51,

thence through aport 10, an annular-duct 1I and the port 82 into the valve chamber I8 of the control'valvaf Such communication may be estab-l thepositionindicatedin-.dotted lines in Fig. 3.

'mennen une/position shown, the piston 'n cuts 'off -eommunicationbetween the' pressure chamber v' "IUI andthe port 1,8,..thereby rendering the contrat;l K 1 valve v88 inoperative.

` `position shown l'in dottedlines. The valve is the disc 8l, 'and having on one face an annular.

seating bead 8l adapted to engage a flat valve seat 8| formed on one side of the-chamber I8 aroundI 1A a port 82. The fluid pressure existing in thek sov to the* controlv valve. through the port 82 so to provide a port 8l, as shown in Fig. l, in comhousing Il, whereby the fluid sump l2. l

The pressure of triennio' tnsfactingagsinst the valve is opposed by centrifugal force developed in the valve element 58 in accordance with the speed oi rotation of thecontrol elementv C', urging position by inertia developed in the valve element munication with the chamber; i3 of the 'clutch'-l mr return' t9 the 3- 58 as a result of angular acceleration in'the rotay tion of the automatic control element C. The di-v rection of rotation is indicated bythe arrow 84 in Fig. 3. A strut 65 is interposed between the valve element 58 and the side of the chamber 59 opposite the seatV 8l. The opposite ends of the4 strut 65 are seated respectively yin a notch 66 inu the valve element 58, and anotch 81 in the valve `chamber 59. The strut 6l is inclined outwardly and toward the direction of rotation, whereby the inertia of the valve element 58 tends to cause it to move relatively in the opposite direction, and

to straighten thestrut 65 towardv a position at i right angles to thevalveseat 8l, resulting in the i valve element-58 being lurged outwardly againstw the seat.`

The use 'of astrut, loosely notchedy into the valve element, as shown, is preferred becausel itis a relatively simple arrangement. but Yit. will be understood that other means for suspending the` valve element so as to resolve the inertial lag into outward seating pressure,` could equally asf well be employed from a functional standpoint.

In the form of the invention under considera; tion, the pressure fluid, intravelling from v the' motor B to the valve I8, must vfirst pass the lockout valve l1.' .'Accordingly, ifthe latteris closed, v

the valve 58' cannot` function'to relieve pressure in the motonand the latter may therebyfbeslili-v Jected to the'inaximum pressure (leuvefec-libyrrws ms no: the

-l2 through-.'-aradial port 1l inthe disc Il.

` :-I Ii'luid underpressure' for operating the lock-'out y valve Il' is `supplied by ra. trion driven "pump, indicated, schematically at .181m liigrl.I

ThepumpsJI-'may be driven byf any portionI oi!A the power transmitting mechanism which is lo` i catedbetween'the driven clutch disc 22 and the'l 'si drive wheels `'of-'the vehicle.- The outlet of thev pump vil communicates through a `suitable fluid fpath.` such 'asia tubev 18, through av shift valve'itl and ai brakekdump valve 28|. avconnection` 80 t (Figure il)` carried bythe clutch housing Il. and la flexible union 8l. with a passage inthe housf v anual control unit D.. The brake dump valve 2 Iv is for the purpose of releasing` y the pressure in the lock out line whenever the l brakepedal is depressed, so that the clutch may tion ofthe intakes. Such a valve, controlled from the brake pedal of the'vehicle, is shown in Patent. v

, No. 2,236,050, issued in thenames of HaroldNutt t andHarold V. Reed January 28', 1941.Y The pasjj y sage szieadstcfen annmer duct s: (m. 1) wmeh communicatesjwithan axialpassage (indicated in dotted lines) inthe sleeve 48. The passage 84 3l communicates-,with the radial.

range, the lock-'outfvalve 51 will be main- :tained bythe thrust ofthe spring lI8 in the open position vshown in dottedlines'in'Fig. 3. I The; 'icontrol-valvef'ttgwill vtlrierebybefinaintained inkv i. 4eoxninunicati'onl-fvvith the chamber '85 of the iluidq motor-.aandwill,automatically controlv the engageentandidisengagement of the clutch in accord-Qy withiconditions of speed and acceleration.

Provision is made for r the;

is adjusted to the starting rangef' including `neu' when the `transmissionis adjusted tothe startpump. as determined by a control valve ll, which The valve piston-12 is provided with a reduced waist portion 18 vterminating in a skirt portion I4A 'p forming a guide in connection with an end region Y loi' the chamber I8, in which it is slidable.- Bev. tween the skirtj'll and a retainer cup 15 in theend )of the chamberflS, is a compression spring Il whichy urges the `valve piston'l! toward its open ruins vt0 become@ operative only when theftransmissio'n is adjusted l to either the.- intermediate orhigh speed vgear ratio. whlchratios maypfor'convenieneebe re-` gl. ferred to as' the driving range.I Such p'rc'nfision may be in the form of a suitable valve such as! is indicated at IIII adapted tocut off the dis-1 l chargeifrom the pump r'f8 and to ventfthepasg sages 69,11, 84, 82, 88 tothe atmospheric pressure infthe transmission' whenzthe ytransmission When the discharge of the pump 18 is eut off,

v the fluid may be vented through a suitable relief valve incorporated in the pump 18.

When the transmission is adjusted to the driving range and it i no longer necessary or desirable for the clutch to operate centrifugally, fluid under pressure is delivered from the transmission pump 18 into the chamber 69 ahead of the valve element 12, forcing the same back against the pressure of the spring 16 until it cuts on Vcommunication between the ports 68 and 110,

thereby rendering the control valve 56 ineffective to relieve pressure in the chamber 3-5, and allowing such pressure to build up to its maximum as determined by the combination control and relief valve 90 which will presently be described.

Fluid escaping past the'skirt 14 of the valve piston 12 is vented to the sump through an opening 85 in the retainer cup 15, and a port 86 in the disc 34 so as to avoid the building up of fluid pressure behind the lock-out piston.

For push-starting of the vehicle, the transmisclutch system shownY therein is lsimilar to -at described above.with respect to the clutch. he iiuid motor, and the manual control unit D, but differs with respect to the pump arrangement 'and the automatic control unit C. l 4One element side by side,` separated by an annular partition 504, in pump chambers deiined, one bythe casing 50. a peripheral ring 502, and the partition 504, and the other by the partition 504,*a peripheral ring 503, .and the annular plate 50|. The

rotor 55a is driven i'romthe ilywheel through the sion is shifted to either intermediate or high gear, and as the transmission is turned overby the wheels of the vehicle, the pump 18 will be operated and will deliver fluid into the chamber 69 of the lockout Valve, from which it may pass through a port 81 (Fig. 5) into the pressure chamber 35, thereby building up pressure behind the piston and moving the same to clutchengaging position. At the same time, the lockout valve is closed so as to prevent escape through the control valve of the fluid thus delivered to the pressure chamber. y

A check valve 88 (Fig. 5) prevents passage of fluid from the pressure chamber through the port 81 into the lockout valve chamber |59v ahead of the valve element 12, during automatic operation of the clutch, so as to avoid the lockout valve being moved to closed position during this stage of operation. Leakage past the check valve is vented in the "starting range by a groove |0|a (Fig. 6) to assure thatlockout does not occur when it is not desired.

Manual control of the clutch is effected by the manual control valve shown in Fig'. 2. This valve includes a valve chamber 89 in the manual valve casing 50, a poppet type valve element 90 engagsleeve 40, being keyed tothe end oi the sleeve 40 as at 98. The rotor 18a-is keyed at 99 to the driven shaft .23 so as to rotate therewith. Each rotor is provided with a series of radial vanes one each of which is shown in cross section at Each rotor has associated with it an arcuate discharge/port, the one for the rotor 55a being indicated in dotted lines at 45 and the one for the rotor 18a being indicated in dotted lines at 46|. The ports 46 and 46| are connected by an' axial passage 41| extending through the rings 502, 503, and 504 so as toA discharge into the common port 41 leading to the valve chamber 89 and to the port 48 which communicates through the passage 5| with the axial passage 52 in the sleeve 40.

ing the seat 9| formed by the junction between J the chamber 89 and the end face of the casing 50, a control element 92 vleading from asuitable control lever or pedal, and a resilient link, such as a coil spring 93, connecting the element 92 to the valve element 90. The resilient link 93 is of substantial length so as to allow the control pedal or lever to be moved through a fairly wide range of movement, whereby to gradually vary the tension on the valve element 90, and thereby gradually vary the pressure that the valve element 90 is able to maintain in the-chamber 89. (In the fully engaged position, this valve governs the maximum pressure, and therefore acts also as a relief valve.) Since chamber 89 communicates with the pressure chamber 35 of the motor through the radial passage 48, the pressure which may be built up in the motor B may be correspondingly varied.. v

In the modification of the invention shown :in Fig. 4, the control valve element 58h is suspended en a flexible swing 94 anchored at its ends to brackets 95 secured to the disc 34, as at 96. The`l valve is located off center with'respect to a. radius of the disc 34, and is therefore sensitive to An annular passage 552 in the casing 50 communicates with the passage 48 to supply oil under pressure to the spaces 553 defined between the radially inner ends of the varies 55| of the rotor 55a, and the inner extremities of the slots in which these vanes operate, the pressure thus other end with the passage 82 leading to the lockout device. Flow through the line |00 may be cut oir and the line |00 vented to release the uid behind the lockout piston when the transmission is adjusted to the starting range, and opened up when the transmission is adjusted to the driving range.

The invention contemplates a simple, but effective, arrangement for thus'controlling the flow of lockout iiuid in any of the forms of the invention herein disclosed. Such an arrangement includes a valve |0| interposed in the duid line |00, and having three positions of adjustment, indicated in Fig. 6 as high," ,neutralk and second,v such positions corresponding to-the similarly termed positions of adjustment of the transmission. When in the neutral position, as shown in full lines, the valve cuts ofi now through the fluid line |00. When in the second gear position, a restricted port |02 in the valve allows restricted ilow through the line |00. When the valve is ,in

. the high gear position indicated, a full diameter port |03 allows unrestricted flow through the `iluid line |00. The restricted ow oi fluid provided ior in the second gear position gives a permits second gear automatic starts to be com-f occurs. Since no high gear starts are desired; owing `to excessive duration ofrsllp, an unrestricted passage of lockout mild is preferred to prevent excessive slipping vofthe clutch. (When the transmission free-wheels, itis not necessary` ed to engage the inner end of the control valve lock-out will occur tends'A to be lower than that l :through a passage 11a in the disc 34a.

to declutch manually for gear shifting.) At low oil temperatures. the speed at which at which lockout lwilll occur at higher oil. temperatures, due to the fact that the pumps will *operatemore eillciently when the oil 'is thick.

This tendency'is counteracted in second gear stricted enough' to permit' second gear engagement m be muy compared ahead of lock-out,

under all conditions, the slip period may be unduly prolonged under heavy torque loads at high oil temperatures. To correct for this latter cena dition, the invention effects a compromise wherein, under' colder temperatureconditions, lock-4 out may occur slightly before the completion of second gear engagement. The alternative type of control valve shown in Figs. '1 to 11 inclusive are designed to facilitate such correction by providing for the application of lockout pressure directly to the control valve so as to augment the pressurerdeveloped by centrifugal force, in an amount which gradually increases with unceasing' speed,- .as will be more fully pointed out hereinaftex.l

The .valve has an operating lever |04 adapted to be engaged by a projection |05 which 4may beformed on the shift fork |06 which controls the Ashif-ting of the transmission into second and high' speed gears. The shift fork |06 may be'slidable on a rail` |01 in accordance with standard practice in conventional shifting mechanisms, and may be engaged by the lower end |08 of the conventional shifting lever |00. When the shift fork |06 is moved to high gear position,

the valve |0|`wil1 be correspondingly adjusted to the high position shown. The same is true of the second speed gear position.' When the shift lever' |09 is adjusted to neutral position, the valve '|0I will be returned to the neutral position indicated. When the shift lever |09 is adjusted to reverse or low positions, the valve |0| will remain in e neutral Iposition for the reason that the lever portion |08 shifts laterally to engage another shift fork, on another shift rail, for the low and reverse positions, and leaves the fork |06 in neutral position. The other fork and rail are not illustrated for the reason that they are of conventional construction. In the neutral position, oil in line |00 is vented through a groove |0| a in valve |0| to atmospheric pressure inside the transmission case. This oil returns to sump l2 through a communicating passage 202 (Fig. l). An arrangement of control valve and lockout device that is operative in connection with the common circuit type of arrangement shown in Fig. 6, and one that has beenfound to be satisfactory in operation, is shown in Figs. I'1, 8 and 9. Instead of the block type control valve with the swinging strut, we provide a piston type valve, indicated generally at 56a, including a piston 58a, slidable in the valve chamber 59a of a cylinder H0 and adapted to seat against a valve seat Gla at one end of the cylinder |l0. When unseated, the valve allows fluid to escape from the pressure range by the restriction of the` valve port |02.

A Whenseated, the valve closes the port.62a so as hold the pressure within the pressure cham- The lockout device in this form of the invention comprises a plunger also slidable in the cylinder ||0,.having'at one end a stem I 2 adaptelement 58a under pressure imparted to its other vend by fluid entering the lockout chamber 69a Communication between the fluid line |00 and the passage lla may be the same as that shown and described in connectionv with Figs. 1 to `3. Communication between the lockout chamber 69a and. the' pressure chamber 35 is established through a port 01a controlled by a valve 88a which prevents .reverse flow from the pressure chamber to .the

lockout chamber. When the transmission is adjusted to the driving range, fluid under pressure delivered to the chamber 69a through the valve |0 and fluid line |00, will advance the lockout piston |I| into engagement with the control valve 58a, whereby the pressure from the pumps will be applied to both ends ofthe control valve piston 58a, and the latter will' therefore be maintained in closed position by a compression spring I3, disposed in the valve chamber 53a, between the inner end of the valve piston 58a and an annular abutment member lll pressed into the cylinder ||0.

When the transmission is adjusted to the starting range, no fluid will be delivered to the lockout piston from the pumps, and the check valve 88a and the vent |0|a will prevent fluid reaching the lockout piston from the pressure chamber 35. Accordingly. there will be no -uid pressure against the inner end of the control valve element 58a, and the valve element will therefore react in accordance with the force' of fluid pressure, acting against its outer end, opposed by centrifugal force and torsional inertia.

The torsional inertia eilect is provided for in this form of the invention by positioning the valve chamber 0 on an axis that is inclined` with respect to a'radius of .the discla passing through the center of gravity of the valve element 58a. The direction of rotation being as indicated by the arrow 64a in Fig. 7, and the seat- The centrifugal effect i'sretained by locating the valve axis also at an angle to a tangent T to the path of rotation R of the center of gravity of the valve elementia, at the radius R. The axis of the valve is therefore located at an angle intermediate the radius R and the tangent T.

The valve piston '58a and the lockout piston ||I may be made either separately, as shown, or asa'single integral piston assho'wn in the pending application Serial No. 209,450 above referred to. However, it is preferredto make the piston separable, as shown, with the valve piston 58a loosely fitted in tlielchamber I0 so asto be freely movable therein, and the lockout piston snugly fitted so as to hold the oil pressure. '.Being located in a portion of the chamber I0 which projects on the opposite side of its median line from that in which the valve piston 58a is con-V tained, the lockout piston is adapted to react to centrifugal force so as to move away from the valve element 50a when not under fluid pressure,

chamberv 35. through, a Polit 32a Communicating 75 thereby leaving the valve piston 58a free to move without interference from the stem ||2. "li'he4 outer limit of. recession ofthe lockout piston I ||i is determined by contact of a siem ns on the piston I I |,-with a plug |18 closing this end of the cylinder LID so as to form the lockout chamber 68a. The stem||5 prevents the lockout piston tracted position. A

cylinder also serves to minimize the danger .e y 2.828.091 .f as described in connection 'witli'tlieprevious form of the invention.

The lever ||8 multiplies thepressure received from the fluid acting on the plstan |||b... During the centrifugal stage of operation, theflever ||8 serves merely as additional centrifugalV weight,

'from closing the chamber 69a when in its rel of the valve sticking as a result of small particles of dirt entering the cylinder. Furthermore, ther piston 58a may be made hexagonal or relieved in any manner so that the bearing engagement against the wall of the cylinder lili may he conbetween the centrifugal valve and the lockout device, it is possible to provide smooth'second gear starts and to employ the less complicated fluid circuit and pumping arrangement embody- -ing a common discharge from both pumps. Ana other advantage resides in the fact that the automatic control valve is responsive to decelera'- n tion as well las acceleration.

and as a reaction point of, fulcrum for the strut85.` .f

The port 62bopens directly'into thev pressure chamber 35, as'y in the'formoi.'v the invention shown in Fig. 8. The spring |25, acting through "-.the lever H8, servesto hold the valve 56 on its 'seat against gravity `when the engine is at rest.

This permits-push-starting, since, if thevalve 56 were open when .the engine is at rest, the fluid delivered from the transmission pump would pass 56 would remain open.

'throughthe checkvalve 88 int the pressure chamber 35- and thence out through the valve port B2b without building up sufcient pressure to lift'the piston lilb. Consequently. the valve vlit may now be noted thatin leach of the common circuitarrangements shown in Figures 6 to v1'1 inclusive, there is adirect balancing of lock- On the other hand, an automatic control *valve Q of the piston type'shown. in Fig.` 'Lis lmore sub-A- y ject to sticking than theV type shown in Fig. The inclination of the valve with reference to both the radius R and the tangent T resolves the.;

centrifugal force acting on the piston into tw'o components, one of which tends to move the pisx ton along its axis, andthe other of which causes 'f' the piston to bear against theouter side of Lits..

n .v cylinder. This latter component increases in acfcordance-with the divergence between the valve vaxis vand the radius. f I

Accordingly, although the arrangement shown Iin* Fig. 7 has under test given satisfactory service,` fthe' invention contemplates a further improvement in which the advantages of direct physical 'coaction between the control valve and the lockout device are combined with the freedom of movement characteristic of the pivoted strut type valve. Thisimprovement is shown in two forms in Figs. 10 and 11 respectively. In the iorm shown in Fig. 10, the controlvalve 56, all parts v of which are designated by the same -numerals as thoseused in Figs. 1 to 8, is associated with a piston type lockout element, indicated generally at 51h, through the medium of' a lever ||8, pivoted at ||9 in a recess |20 communicatingiwith a f the valve chamber 58, and extending at its other end into the chamberBSb of the lockout device l 51h. A Apush rod |2| at one end engages the free end ofthe lever H8, and has a reduced portion |22 piloted in an opening |23 in said free end of the lever. The other end of the push rod |2| is piloted in a hole |24 in the piston Ib of the lockout device, and is yieldably engaged with the piston |I|b through the medium o'f .a frustoconical compression spring |25, one end of which is engaged against a shoulder |26,on the rod |2|, and the other. end of which engages the piston I Ib. Fluid under pressure is applied to the pis# out pressure and centrifugal force on the one hand against'the pressure in the ychamber 35 on the other hand. yEach' increment'ot combined y lockout and centrifugal pressure develops a cor- Y responding proportional'increment of pressure in the'cylinder 35, i. e., the-pressure oi.' the uid in theV chamber 35 is directly` proportional to the -sum of lockoutand, centrifugal pressure. ,This

feature,:in combination with the restricted second gear portj||l2l in the lockout transmission line |00, has provided smooth automatic engagements under all conditions. v

In the form of the invention shown in Fig. 11,l

the lockout piston lllc, springV |25c, push rod 10. The valve 56e, however, is arranged in direct association with the push rod l i2 |c, the multiplying lever being omitted, and the upper end |22c of the push rod being piloted in a holeA |28 in the valve element 58e. The axis of movementof the valve element 58e is inclined intermediate a radius and tangent of its path of rotationso as to renderthe valve element responsive to both centrifugal force and torsional inertia. Itis suspended out of contact with' the sides of the chamber 59e, by three struts 65o, notched into the valve element and the housing 34e, at 66o and 61e respectively, thevalve chamber 59e communicating with the pressure chamber through a port 62e, and with the interior of the clutch housing in the same manner as shown in Fig. 1.

In the operation ofthe system shown in Figs.

6 to 11 inclusive, the clutch, which may heA of the same construction as that shown in Fig. 1,

when Ithe engine and vehicle are both motionless,

- maintained by the retractor springs 30 in disengaged position. Under a normal start, when the engine is first started, the rotation of the fly- .wheel will be.' transmitted to the automatic control unit C, to the clutch pump, and to the tan.- dem pump unit E. The latter will commence, to pump fluid into the motor B. During the early stage of operation, prior to the attainment of suilcient speed of rotation to cause the centrifugal control valve to close against the pressure of the fluid thus being delivered to the motor, such ilud will escape from thepressure chamber 35 through the -ports 62a, B2b, or 62e, as the case may be, into the control valve chamber and thence through the 'port 53a. or |20, back to the sump I2` of the i clutch The. transmisnon being adjusted te tnefatmma range', newIv e control valve will respond to acceleration,l and will close mor'equi'ckly. 1i.' el; at'aylower speed than under slow acceleration;x Thiscompensates for the lag in completion ot ,clutch engagementl subsequentto the closing of ,the valve, such lag being occasioned by thenecessity for building up the pressure to the engagement level, and the necessary period of time to move the .pressure f plate into' contact withv the clutch discfor initial f transmission of torque. i v

When the transmission isshifted to the drivi ing range`iluid fromthe pumping unit is routed i' through the fluid line ill) to the lockout chamber,

causing the lockout piston to transmlt'jpositive closing pressure to the control valve, therebyif preventing the latter from opening even though the speed of rotation should drop below thecritical speed for centrifugal closing. Thisfacilitates slippage of the clutch while operating in the matic control valve, and thereby minimizes wear on the clutch facings. I

When the brake pedal is depressed; the clutch is prepared for centrifugal disengagement by the brake dump valve which cuts off the admissionV of pressure into passages l2, 8 3, lla, etc.,

and "dumps or vents the oil "in these passages .s vand the lockout. chamber.

will then respond to centrifugal Vi'orce and move l to its retracted position. allowing the control valve to freely act under the pressure vof the 'uid in' ,the pressure chamber andmove to open position Q thereby engagement or release of the clutch can The lockout piston as soon as such pressure overbalances the combined effect of centrifugal force and the spring H3 or |25. as the case may be. vThe opening of the valve will release the pressure in the pressureV chamber and allow the clutch retractor` springs to disengage the clutch Just before the vehicle comes to rest,the'reby eliminating thenecessity for doing this manually. l

Under push-starting conditions, the control valve will be held in closed position' by the spring i I il or |25 while theiluid output from the pumping unit is delivered simultaneously to the pressure chamber," and to the lockout chamber.

A"1r f The fluid pressure on both ends of the control valve being thus. maintained in a balanced state, spring pressure 'will maintain the valve closed while the pressure builds up to the point of clutch engagement. The action of the spring, in the form shown in Fig. '7, may be assisted by a small excess of force behind the lockout piston over 1 that acting against the seating end of the control C valve piston, the diameter of the lockout piston being somewhat larger than that of the seating `end `of the valve piston. In the form shown in Fig. 10, the multiplication obtained through the 'lever i I8 is suillcient at least to balance the pres- .ipressureacting on'the-largerarea "of the contgl valve element x form of the invention shownin Figsl. to 3 has N .ready been given and need not be repeated here.

chamber,v hasproven to be adistinct improvement overth'e earlier proposed centrifugal,v valve y the' ehamber.

:One advantage of the pressure regulating" valve of the present invention is that it elimi- '51 fnates the necessity for employing strong react- 20 ance springs to-oppose the action of centrifugal forcefin controlling the movements of the valve,

the opposing pressure being supplied by the fluid acting against one/end of the valvev element. Where-strong reactance springs are employed,

25. difcultyA in securing lockout is,` experienced,

whereasthe present invention produces the lock- `out without diillculty, and by 'a proportional v'actiox1.whicl r `gives smoother engagement.

",-jAnother advantage of the valve of the present aoginventlon isthatit permits of considerable sim-1` driving in tramo conditions; where `itmay be desirable to slow down below such critical speed or the engine iiywheel, without shifting the transmission back into low gear. This lockout condition will exist as long as the vehicle is being driven in either second or high gear. It prevents .rpliilcation ascontrasted to prior arrangements. Another vof the improvements contemplated by ythe present invention is the arrangement oi' the "control v'valve to vrespond both to its centrifugal 3i.Violine and its torsional inertia. A complete disi i 'cussionof this feature has already been given 'herein and -need not be repeated here.

rAnother important improvement contemplated by the presentinvention is the arrangement .wherein'ithe lockout iluid is delivered not only gagement. This is true in all forms of the invention shown herein, whether the pumps deliver through a common outletport, or through sepa" rate circuits. Since either or both pumps feed fluid directly to the fluid motor, -controlof the pressure therein can be eiected by varying the load on the manual control valvev spring, and

`in full control of the pressure in the filuid motor,

it is impossible for the pumps to causethe presg sure to build up quickly again to the clutch engagement level if the valve is not in the position of full spring extension corresponding to full clutch engagement pressure. When it is desired to reengage the clutch, suchreengagement may be accomplished gradually under full control by the operator, by slowly releasing the clutch pedal so as to gradually increasethe tension on thev manual control valve spring, therebygradually building up the pressure to the engagementlevel.

Another improvement contemplated in the present invention is the employment of a lockout plunger, physically associated with the con- 170 trol valve so as to transmit pressure directly thereto, but separate therefrom so as to be adapted to move away from the control valve when not subject to-thepressure of the lockout nuid, and thereby allow the control valve to move freely in the centrifugal stage' of operation without the ieexeut einen i l v|15 against A detailed atatem ntdrfthe epeau'dn of the y' -f.The employment of a centrifugal ,valvewhich 'j regulates vthe pressure lin the pressure chamber -of the clutch, by direct transmission oithe cen-A A1 0 trifugallydeveloped pressure tothe iiuid in'the tothe lockout mechanism, but also to the pressure chamber of `theiiuid motor, through a check valve, the same as the fluid for centrifugal enl 8 hindrance from the-lockout *This arrangement also makes it possible for the control valve to be loosely mounted in its chamber so as to further facilitate freedom of movement.

Another advantage of theinvention, as embodied in the form shown in Fig. 6,' is the sim'- f plified pumping arrangement and pumping c irycuit which is made possiblein vthis construction.

The separate circuit form of the invention shown in Figs. 1 to s is suitable for use with an automatic transmission where a separateoil f. pump is used for oontrollingthe transmission shifting mechanism, and where it is important, v

that the oil pressure delivered by this pump be maintained when the clutch is manually released at high car speed soA that such automatic transgear as aresult .of the drop in oil pressure.

Weclaim: Y. l. In an automatic clutch system for a motor vehicle: a fluid operated clutch comprising driving and driven frictionI clutch elements, meansfor supplying fluid under pressure for operating the clutch, and a control valve rotatable with` one of the clutch elements and responsive to the opposed forces of fluid pressure inthe system, tending to open it, and centrifugal force and rotational inertia, tending to close it, said valve being adapted to automatically control the fluid 1 pressure acting upon said clutch.

2. In an automatic clutch system for a motor vehicle, `a fluid operated clutch, means-for supplying 'fluid underpressure for operating the clutch, and a control valve including a rotatable valve-housing and a valve element therein adapted to automatically control, the application of vfluid pressure to the clutch in response to both n centrifugal force and rotational inertia devel oped in said valve element.

3. In an automatic' clutchvsystem for a motor vehicle,'a uid operated clutch including driving and driven friction clutch elements, means for Supplying fluid under pressure for operating the clutch, and a control valve including a valve housing rotatable with thedrlving element and having a valve chamber provided`with a valve seat, a block valve element in said chamber adapted to engage said seat under the effect of centrifugal force, and a pivotal connection between said valve element and said valve housing, adapted to guide said valve element toward seating trol valve including a rotatable valve housing and a speed and torsional inertia-responsive valve element therein arranged to open-.under pressure ofthe fluid acting on the clutch so as to limit l suchrv pressure in accordance .with.centrifugal ,force and torsional inertia developed in said valve `mission willnot suddenly shift to low or second `trol the pressure of the fluid acting onthe clutch,

and fluid operated means,l operative onlyv when` the transmission is adjusted to its driving range,v ,for rendering said valve inoperative to relieve pressure.

6. Inganautomatic clutch system foramotor-f vehicle-including a changesped' transmission having a starting range and a driving range; a

fluid operated clutch, means for supplying fluid under-pressure for operatingthe clutch, a conelenient,a lockout piston rotatable'withsaid control valve and mechanically connected thereto. and means for conducting fluid to said piston l when the transmission is adjusted to the driv-` 4 ing range, wherebytoslock saidvvalve inclosed4 7. In'an automatic clutch system for amotor vehicle including echange speed transmission having a startingrange anda driving' range. al 1 fluid loperated clutch, means for supplying uid 1 under pressure for operating the clutch, a control'valve including a valve housing rotatable position under the effect of rotational inertia ofI said vvalve element.

4. In an automatic clutch system for a motor vehicle including achange speed transmission having a starting range and adriving range, a fluid operated clutch, means for supplying uid under pressure for operating the clutch, a control valve including a valve housing and a speed and rotational inertia responsive valve element,

arranged to open under pressure of the fluid act-1 ing on the clutch so asto limit such pressure in accordance with centrifugal force and rotational inertia developed in said valve element, and means, operative only when` the transmission is adjusted to the driving range, to render saidvalve f inoperative to limit said pressure. 5. In an automatic clutch system for a motor vehicle including a transmission having a start# ing range and a driving range; afluid operated clutch, means for supplylngfluid under pressure to said clutch for operating the same, a control valve including a rotatable vvalve housing and a speed and torsional inertia responsive valve piston therein arranged tojbe urged toward open with the driving element and havingv a valve chamber and a control piston therein arranged to be urged toward open position by fluid pressure acting 'on the clutch and'toward closed position by centrifugal force, alockout piston in said chamber, and means, operative when the transmission is adjusted to the driving range, to direct fluid under pressure against said lock'- out piston, whereby to cause said lockout piston to engage the control-piston and lock the latter in closed position irrespective of centrifugal orce.

- 8. A clutch system as deflned'in claim 7, wherel in said control piston is loosely mounted in the chamber, and the lockout piston has substantially fluid-tight engagement with the wall of the chamfber. l

9. A clutch system as defined in claim '1, wnerein said control pistonis loosely mounted in the chamber and said lockout piston has substan-- muy mud-.tight engagement with the wan o'f the chamber and is arrangedvto be urged away a from saidv control piston by centrifugal force when not acted upon by the lockout fluid.

10. In an automatic clutch system for a motor i vehicle, a fluid operated clutch including drivl in g and driven friction clutch elements, means for supplying fluid under pressure 'for operating the clutch, andl a. control valve including a valve housing rotatableA with the driving element and v having a valve chamber provided with a valve seat. a` block valve element in said chamber adapted to engage said seat under the effect of centrifugal force, a .st-rut inclined to the plane of spectiveof inertia, and means, operative when the transmission is adjusted to the driving range.

position by fluid pressure applied to the` clutch i' and-toward closed position by centrifugal force fand torsionalinertia so as to automatically'conl' for conveying fluid under pressure to said lockout piston for operating the same.

l1, In an automatic clutch system for a motor vehicle including gear shifting mechanism comprising a pair of shift rails, shifting forks carried by said rails and an actuator selectvely engageable with said forks, and a transmission having a starting range controlled by one of said forks and a driving range controlled by the other fork; a clutch, fiuid operated speed responsive mechanism for automatic operation of the clutch, fiuld operated lockout mechanism for locking the clutch in engagement irrespective oi speed, and a valve, controlled by the fork which controls the driving range, for admitting fluid to said lockout mechanism for effecting lockout when the transmission is adjusted to the driving range.

12. In an automatic clutch system for a motor vehicle `including gear shifting mechanism comprising a pairof shift rails, shifting forks carried by said rails and an actuator selectively engageable with said forks, and a transmission having a starting range controlled by one of .said i'orks and a driving range controlled by the other fork; a clutch, iiuid operated speed-responsive mechanism for automatic operation of the clutch, fluid operated lockout'mechanism for locking the clutchinfengagement irrespective of speed, and a valve, controlled by the fork which controls the driving range, for admitting iiuid to said lockout mechanism for effecting lockout when the transmission is adjusted to the driving range.

13. In an automatic clutch system for a motor v vehicle including a transmission having a starting range and a driving range; a clutch, a fluid motor for exercising a controlling effect upon the clutch', means for supplying fluid under pressure to said motor. speed-responsive mechanism for controlling automatic operation of the clutch,

' fluid operated lockout mechanism operative when the transmission is adjusted to the driving range to modify the action of said speed-responsive mechanism so as to cause the clutch to become locked in engagement irrespective of speed, a

port for allowing iluid to pass from the lockout mechanism into said motor, and a one-way valve closing said port against passage of fluid therethrough in the reverse direction.

14. In an automatic clutch system for a motor the pressure of fluid in the motor and toward 4closed position =by centrifugal force, fluid-operated lockout mechanism operative wheny the transmission is adjusted to the driving range to render said valve inoperative to relieve pressure, so as to vcause the clutch to become locked in engagement irrespective of speed, a port for allowing uid to pass from the lockout mechanism into said motor, and a one-way valve closing said port against passage of verse direction.

15. In an automatic clutch system for a motor vehicle including a transmission having a starting range and a driving range: a clutch including driving and driven friction clutch elements, a fluid motor for exercising a controlling' eiect on said clutchl an engine driven pump,

rotating iwith the driving element of the clutch,

' clutch, means for supplying fluid under pressurefluid therethrough in the refor normal operation thereof, speed-responsive means for controlling an automatic stage of such normal operation, a fluid-operated lockout mechanism for modifying the action of said speed-responsive means so as to cause the clutch to become locked in engagement irrespective of speed, a pump driven by the vehicle, adapted, when the transmission is .adjusted to the driving range, to supply uid to said lockout mechanism through conducting passages separate from those leading from the engine driven pump to the motor, a port for allowing iiuid to pass from said lockout mechanism to said motor for operating the motor when the engine driven pump is inoperative, and aone-way valveclosing said port against passage oi' fiuid therethrough in the reverse direction.

16. In an automatic clutch system for a motor vehic1eincluding a transmission `'having a starting range and a driving rangerfa clutch. a duid motor for exercising a controlling eect on the clutch, means for supplying fluid under pressure to said motor, speed-responsive means for controlling automatic operation o! the clutch, fluid operated lockout mechanism operative, when the transmission is adjusted to the driving range, to

and resilient means connectingsaid manual control element to said valve.

17. In an automatic clutch system for a motor vehicle including a transmission having a starting range and a driving range; a clutch. a fluid motor for operating the clutch, means for supplying fluid under pressure to said motor, a speed-responsive valve arranged to be urged toward open position by the pressure of the fluid in the motor and toward closed position by centrifugal force, uld operated lockout mechanism operative when the transmission is adjusted to the driving range to render said valve inoperative to release pressure whereby to cause the clutch to become locked in engagement irrespective of speed, a port for allowing uid to pass from the lockout mechanism into said V motor, a one-way valve closing said port against passage of fluid therethrough in reverse direction, and manual control means including a valve in communication with the fluid motor, adapted when opened to relieve the pressure of the uid therein, a manual control element, and a yieldable connection between said manual control element and said valve.

18. In an automatic clutch system for a motor vehicle including a transmission having a starting range and a driving range; a clutch, a uid motor for exercising a controlling eiect on the to said motor, speed-responsive means for controlling automatic operation of the clutch. .fluid operated lockout mechanism operative, when the transmission is adjusted to the driving range, to

cause the clutch to become locked in engagement irrespective of speed, a port for allowing fluid to pass from the lockout mechanism to 'said motor, and manual control means including a valve chamber in communication with both said Y for supplying fluid under pressure to said motor motor an.. said lockout mechanism and having an outlet for releasing fluid, a valve closing said outlet, a manual control element, and resilient' tension means connecting said manual controlv adapted, when not undermanual control, to

automatically limit, at a predetermined maximum, the pressure developed in said motor by i position to the iiuid pressure, and control means.

for varying the tension in said resilient means.

20. In an automatic clutch system for a motor vehicle, a clutch, a fluid motor for exercising a controlling efect'upon the clutch, means for supplying fluid under pressure to said motor, speed responsive means for automatically vary- Aing thev pressure of the fluid in said motor,

mechanism for manually controlling pressures in the motor, said mechanism including means forming an outlet for releasing fluid from said motor, a valve closing said outlet, said valve tending to open under the iiuid pressure in said motor, resilient means acting upon said valve so as to urgethe valve toward its closed position in opposition to the iiuid pressure, and conl trol means for varying the tension in said resilient means.

21. In a powerl transmission system for a motor vehicle including driving and driven members,l fluid operated mechanism for establishing a drive connection between said members, means for supplying iiuid under pressure to said mechanism for operating the same, and a control valve including a valve housing rotatable in timed relationship with one of said members and having a valve chamber, and a valve element in said chamber, movable in a path at an angle with reference to a tangent to the path of rotation of the center of gravity of said element and at an angle to a radius of the center of said path, passing through said center of gravity, said valve element being adapted to control the application of fluid pressure to said mechanism in response to both centrifugal force and rotational inertia developed in said valve element. 1

22. In a power transmitting system for a motor vehicle including driving and driven members and a change speed transmission having a starting range and 'a driving range, fluid operated mechanism for establishing a driving connection between said members, means for supplying fluid under pressure to said mechanism for operating the same, -a control valve including a valve housing rotatable in timed relationship to the rotation-of one of said members, said housing having a valve chamber, avalve element in said chamatan angle to a radius ofthe center of said -path passing through said center of gravity, said valve element being adapted to be urged toward open lposition by iiuid pressure acting on said mechanism and toward closed position by the combined effect of its withindeveloped centrifugal force and rotational inertia. whereby to control said iluid pressure, and means, operative when the transmission is adjusted to the driving range, toapply fluid pressure against said valve element so as to lock the same in closed position irrespective of the action of centrifugal forcevory rotational inertia.

23'. In apower transmission system for a motor vehicle having driving and driven members, mechanism for establishing a drive between said members; iiuid operated means for exerting a 'controlling eifect on said mechanism,- a pair of fluid pumps, driven by the driving and driven members respectively, arranged to deliver fluid under pressure to said iiuid operated means for operating the same, and means for exerting control upon the pressure of said fluid, including a valve casing rotatable in timed relationship to the rotation of one of said members and a valve element therein arranged to respond to uid pressure in said fluid operated means tending to open lt and its within developed centrifugal force tending to close it.

24.' In a power transmission system for a motor vehicle having driving and driven members, fluid operated mechanism for establishing a drive between said members, a pair of pumps, driven by the driving and driven members respectively, arranged to deliver fluid under pressure to said mechanism for operating the same, and means for exerting control upon the fluid pressure in said mechanism, said means comprising a manually operable valve and a centrifugal valve, the llatter including a valve casing rotatable in timed relationship to the rotation of one of said members, and a valve element therein arranged to respond to the fluid pressure inl said mechanism tending to open it and its within developed centrifugal force, tending to close it, said Valves being adapted, in one combination of positions, to relieve the uid pressure and in another combination of positions, to maintain the fluid pressure.

25. In a power transmission for a. motor vehicle having driving and driven members,-mech anism for establishing a drive between said members, a iluid system for exerting a controlling effeci; on said mechanism, said iluid system including a pair of fluid pumps, driven by the driving -member and driven member. respectively, said driving member operated pump being arranged to deliver iiuid under pressure in said system and means for exerting control upon the fluid pressure in said uid system, including a valve casing rotated by said driving member and a centrifugal force responsive valve element therein arranged to respond to fluid pressure in said fluid system vtending to open itIk and the combined effect of its Within developedY centrifugal force and fluid pressure coming only from said driven memberV operated pump, tending to close it.

26. In a power transmission system for a motor vehicle having driving and driven members, fluid operated clutch mechanism for establishing a drive between said members, means for delivering fluid under pressure to said mechanism for operating the same, and means for exerting control upon the iluid pressure in said mechanism,

including a valve casing rotatable in timed relationship with one of said members and a valve element therein arranged to respond to fluid pressure in said mechanism tending to open it and the combined efl'ect of its within developed centrifugal force and fluid under pressure from said fluid delivering means. tending to close it.

27. In a power transmission for a motor vehicle having driving and driven members, and including a change speed transmission having a starting range and a driving range, including intermediate and high speed gear ratios, mechansm for establishing a drive between said members, a fluid system for exerting a controlling effect on said mechanism, said system including means for delivering fluid under pressure in said fluid system for normal drive control, and means for exerting control upon the fluid pressure in said fluid system, including a valve casing rotatable in timed relationship to the rotation of one of said members and a valve element therein arranged to respond to nuid pressure in said uid system tending to open it and the combined effect of its within developed centrifugal force and fluid under pressure delivered from said fluid delivering means, tending to close it, and a flow restricting valve interposed between said fluid delivering `viding a valve chamber rotatable in timed retor vehicle having driving and driven members,

a clutch for establishing a drive connection between said members, a fluid motor for operating said clutch, means for delivering fluid under pressure to said motor, means providing a valve chamber rotatable in timed relationship to the rotation of oneoi.' said membersfa centrifugal force responsive valve element in said chamber adapted to move under centrifugal force against the pressure of the fluid in said motor, toward means and said valve for restricting the flow of fluid which tends to close the valve, said flow restricting valve being arranged to be operative when the transmission is operating in the intermediate speed ratio.

28, In a power transmission system for a motor vehicle having driving and driven members, mechanism for establishing a drive between said members, a fluid motor for exerting a controlling effect upon said mechanism, means for delivering fluid under pressure to said motor, and means for exerting control upon the fluid pressure in said fluid motor, including a valve casing rotatable in timed relationship to the rotation of one of said members and a valve element therein arranged to respond to the pressure of fluid in said motor tending to open it and its within developed centrifugal force tending to close it.

29. In a power transmission system for a motor vehicle having driving and driven members, mechanism for establishing a drive between said members, fluid operated means for exerting a controlling effect upon said mechanism, said means including a fluid pressure chamber and an element therein movable under fluid pressure, and means for exerting control upon the fluid pressure in said chamber, including a valve casing rotatable in timed relationship to the rotation of one of said members and a centrifugal force responsive valve element therein, and a passage establishing communication at all times between the fluid in said chamber and said valve element so as to oppose the pressure of the fluid in said chamber against the centrifugal force developed in said valve element.

30. A power transmission system as defined in the preceding claim, wherein said valve casing is provided with a fluid escape port communicating with. said passage, said valve element tending to close said port under the effect of centrifugal force.

31. In a power transmission system for a motor vehicle having driving and driven members,

a clutch for establishing a torque transmitting connection between said members, a fluid motor for operating said clutch, means for delivering fluid under pressure to said motor, means proclosed position wherein it permits said pressure to build up in the motor for effecting clutch engagement. and selectively operable means for directing fluid under pressure into said chamber for action against said valve element to maintain said element in said closed position and thereby lock out the clutch against centrifugal disengagement.

33. In a power transmission system for a motor vehicle having driving and driven members, a clutch for establishing a drive between said members, a fluid motor for operating said clutch, a pump, driven by the driving member, for delivering fluid under pressure to saidmotor for operating the same, means providing a valve chamber rotatable in timed relationship to the rotation of one of said members, a centrifugal force responsive valve element in said chamber adapted to move under centrifugal force against the pressure of the fluid in said motor toward a closed position wherein it permits fluid pressure to build up in said motor for effecting clutch engagement, and means including a pump driven with the driven member, for applying fluid under pressure into said chamber against said valve element'to maintain the same in clutch engaging position and thereby lock out the clutch against centrifugal disengagement.

34. In an automatic clutch system for a motor vehicle, a fluid operated clutch including driving and driven friction clutch elements, means for clutch, and means for controlling said pressure,

'including a valve housing rotatable in timed relationship to the rotation of one of said elements and having a valve chamber provided with a valve seat, a block valve element in said chamber adapted to engage said seat under the effect of centrifugal force, anda strut inclined to the plane of said valve seat, having one end pivotally engaging the valve element opposite the seat and adapted to guide the valve element toward seating position under the effect of rotational inertia developed in the valve element.

35. In a power ytransmission for a motor vehicle having driving and driven members, means for establishing a drive between said members, a fluid system for exerting a controlling effect on said means, said system including means for developing pressure in the fluid and a control valve for controlling said pressure, said valve including means forming a valve chamber rotatable in members and a valve element in said chamber,

arranged for movement in a'path disposed at an i angle to a tangent tothe path of rotation of the center of gravity of said valve element and atA an angle to a radius of/the center of said Path passing through said center of gravity, said valve element being adapted to be urged toward open position by fluid pressure acting on said mechanism and toward closed position by the combined effect of its within developed centrifugal force and rotational inertia.

36. In an automatic clutch system for a motor vehicle, a uid operated clutch, means for supplying iiuid under pressure for operating the' clutch, and a control valve including means forming a rotatable valve chamber and a valve element therein, arranged 'for movement in a path dls' posed at an angle to a tangent to the pathof rtation of the center of gravity of said valve element and at an angle to a radius of the center of said path passing through said center of gravity, said valve being adapted to automatically control the application of fluid pressure to the clutch in response to both centrifugal force and rotational inertia developed in said valve element.

3'7. In an automatic clutch system for a motor vehicle including a transmission having a'starting range and a driving range; a fluid operated clutch, means for supplying fluid under pressure to said clutch for operating the same, a control valve including means forming a rotatable valve chamber and a valve element in said chamber, arranged for movement in a path disposed at an angle to a tangent to the path of rotation of the center of gravity of said valve element and at an angle to a radius of the center of vsaid path passing through said center of gravity, said valve element being adapted to be urged toward open position by fluid pressure acting on the clutch and toward closed position by me oombined @soot of its with,- in developed centrifugal force and rotational in,- ertia, whereby to control said fluid pressure, and

`means, operative only when the transmission ls adjusted to the driving range for rendering said valve element inoperative to relieve the fluid pressure in the clutch.

38. In a power transmission system fora motor vehicle including driving and driven members; mechanism for establishing a drive between said members, a fluid system for exerting a controlling p, 2,328,091l timed ronnonship to the rotation of one of said fluid, and means for exerting control upon s id pressure, including means forming a rotatale 4 valve chamber driven by one of said members and a valve element therein arranged for movement effect on said mechanism,v said system including means for developing pressure in the fluid in the system, speed responsive means for automatically varying the said pressure, said speed responsive means including means forming a valve rotatable chamber driven by one of said members and a valve element therein arranged for movement in a path disposed at an angle to a tangent to the path of rotation of the center of gravity of said valve element and means for over-controlling said pressure, said means including a vent, a valve for closing said vent, said valve tending to open under thev pressure in said piston, resilient means acting upon said valve to urge it toward its closed position in opposition to the fluid pressure, and operator controlled means for loading said resilient means. Y

39. In a power transmission for a motor vehicle having driving and driven members, mechanism for establishing a drive between said members, and a fluid system for exerting a controlling effect on said mechanism, said system including a pair of pumps, driven by the driving and driven members respectively for developing pressure in the in a path disposed atan angle to a tangent to the path of rotation of its center of gravity, and adapted to respond to said fluid pressure tending to open it and its within developed centrifugal force tending to close it.

40. In a power transmission for a motor vehicle having driving and driven members, mech anism for establishing a drive between said membersl and a fluid system for exerting a controlling effect upon said mechanism, including a pair of pumps, driven by the driving and driven mem# bers respectively, arranged to develop pressure in the fluid in said system, and control means comprising a manually operable valve and a centrifugal valve, the latter including means forming a rotatable valve chamber driven by one of said members and a valve element therein arranged for movement in a path disposed at van angle to a, tangent tol the path of rotation of its center of gravity, and adapted to respond to the fluid pressure in said system tending to open it and lts within developed centrifugal force tending to close it, said valves being adapted, in one combination of positions to relieve the fluid pressure and in another combination of positions, to maintain the liuid pressure.`

4l. In a power transmission for a motorvehicle having driving and driven members, mechanism for establishing a drive between said members, and a fluid system for exerting a controlling effect on said mechanism', including a pair of fluid pumps, driven by the driving member and driven member respectively, said driving member operated pump being arranged to deliver fluid under pressure in said system for normal clutch operation, and means for exerting control upon said uid pressure, including means forming a valve chamber rotated by said driving member and a valve element therein, arranged for movement in a path disposed at an angle to a tangent to the path of rotation of the center of gravity of said valve element and adapted to respond to fluid pressure in said system tending to open it and the combined effect of its within'developed `centrifugal force and uid pressure from said driven member operated pump, tending to close it.

42. In a power transmission for a motor vehicle having driving and driven members, mechanism for establishing a drive between said members, a fluid system for exerting a controlling effect on said mechanism, means for delivering fluid under pressure in said system, and means for exerting control upon said pressure, including means forming a rotatable valve chamber driven by one of said members and a valve element therein arranged for movement in a path disposed at an angle to a tangent to the path of rotation of the center of gravity of said valve for establishing a drive between saidlrnembers,

and a fluid system for exerting a controlling effect upon said mechanism, including a pair of uid pumps, driven by the driving member and driven member respectively, adapted to develop pressure in the fluid in the System, speed responsive means for controlling said pressure. including means forming a rotatable valve chamber driven by one of said members and a valve element therein arranged for movement in a path at an angle to a tangent to the path of rotation of the center of gravity of said valve element, and adapted to respond to :luid pressure in the system tending to open it and its within developed centrifugal force tending to close it.V v

and means for over-controlling said pressure,

comprising a vent for releasing fluid from they pislton, a valve controlling said vent, and operator- 5 controlled means for operating said valve.

HAROLD NU'rr. merano n sMmL. 

